package com.joshua.spring.socket;

import com.joshua.spring.util.JacksonUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * projectName feign-test
 * package com.joshua.spring.socket
 * classname  WebSocketServer
 * <p>
 * description
 * </p>
 *
 * @author <a href="mailto:joshualwork@163.com">joshua_liu</a>
 * @date 2020/10/28 15:11
 */
@Slf4j
@ServerEndpoint("/web-socket/{userId}")
@Component
public class WebSocketServer {
   

    /**
     * 静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
     */
    private static int onlineCount = 0;
    /**
     * concurrent包的线程安全Map，用来存放每个客户端对应的MyWebSocket对象。
     */
    private static ConcurrentHashMap<String, WebSocketServer> webSocketMap = new ConcurrentHashMap<>();
    /**
     * 与某个客户端的连接会话，需要通过它来给客户端发送数据
     */
    private Session session;
    /**
     * 接收userId
     */
    private String userId = "";

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("userId") String userId) {
        String $aaa= "";
        this.session = session;
        this.userId = userId;
        if (webSocketMap.containsKey(userId)) {
            //加入Map中
            webSocketMap.remove(userId);
            webSocketMap.put(userId, this);
        } else {
            //加入Map中
            webSocketMap.put(userId, this);
            //在线数加1
            addOnlineCount();
        }
        log.info("User {} connect success,online user num {}", userId, getOnlineCount());
        try {
            sendMessage("Connect success");
        } catch (IOException e) {
            log.error("User {} network  anomaly", userId);
        }
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        if (webSocketMap.containsKey(userId)) {
            //从map中删除
            webSocketMap.remove(userId);
            //在线数减1
            subOnlineCount();
        }
        log.info("User {} logout,online users num {}", userId, getOnlineCount());
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        log.info("User {},message {}", userId, message);
        //可以群发消息
        //消息保存到数据库、redis
        if (!StringUtils.isEmpty(message)) {
            try {
                //解析发送的报文
                Map<String, Object> map = JacksonUtils.json2map(message);
                //追加发送人(防止串改)
                map.put("fromUserId", this.userId);
                String toUserId = String.valueOf(map.get("toUserId"));
                //传送给对应toUserId用户的websocket
                if (!StringUtils.isEmpty(toUserId) && webSocketMap.containsKey(toUserId)) {
                    webSocketMap.get(toUserId).sendMessage(JacksonUtils.mapToJson(map));
                } else {
                    //否则不在这个服务器上，发送到mysql或者redis
                    log.error("User {} not online", toUserId);
                }
            } catch (Exception e) {
                log.error("Receive client message {},but push message fail", message);
            }
        }
    }

    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        log.error("User {} on error,due to {}", this.userId, error.getMessage());
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }


    /**
     * 发送自定义消息
     */
    public static void sendInfo(String message, @PathParam("userId") String userId) throws IOException {
        log.info("Send message to user {},message {}", userId, message);
        if (!StringUtils.isEmpty(userId) && webSocketMap.containsKey(userId)) {
            webSocketMap.get(userId).sendMessage(message);
        } else {
            log.error("User {} not online", userId);
        }
    }

    private static synchronized int getOnlineCount() {
        return onlineCount;
    }

    private static synchronized void addOnlineCount() {
        WebSocketServer.onlineCount++;
    }

    private static synchronized void subOnlineCount() {
        WebSocketServer.onlineCount--;
    }
}